A method for preparing a superhydrophobic coating

Abstract

The application relates to a preparation method of a super-hydrophobic coating and belongs to the technical field of material surface treatment, and comprises the following steps: uniformly mixing bisphenol A diglycidyl ether and polymethyl methacrylate, adding solidifying agent particles and stirring for 5 min to obtain a blend; dissolving a photo initiator in an active diluent to form a uniform mixed solution, then adding a modified polyurethane adhesive, the blend and modified polyaniline fibers to obtain a sprayable colloidal suspension; and then uniformly spraying the sprayable colloidal suspension onto the surface of a base material to obtain the super-hydrophobic coating. In the technical scheme, 800-mesh sandpaper is used to abrade the coating at a pressure of 2.2 KPa, and the result shows that the coating still has super-hydrophobicity after 200 abrasion cycles, and the water contact angle is 155 degrees.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of material surface treatment, and particularly relates to a preparation method of a super-hydrophobic coating. BACKGROUND

[0002] The wettability of a liquid on a solid surface is a very important aspect of material science and surface chemistry, which has various practical applications in daily life, industry and agriculture. In principle, when a liquid droplet contacts a solid surface, it will either remain spherical or spread on the surface to form a thin liquid film, exhibiting hydrophobicity or super-hydrophobicity. The contact angle refers to the angle formed by the liquid at the three-phase boundary of the liquid, gas and solid, between the tangent plane of the liquid surface and the tangent plane of the solid surface, and is used to measure the wettability of the liquid on the solid, which has the advantages of being intuitive and the disadvantage of being unable to reflect the energy change of the wetting process.

[0003] At present, great progress has been made in the preparation of super-hydrophobic coatings, and many preparation methods have been successively developed, and considerable results have been achieved in the treatment of pollutants in industrial production. This has to some extent protected the ecological environment, improved the industrial production efficiency, reduced the consumption of raw materials and energy, and brought great benefits to production and life. Nowadays, the hydrophobicity of organic-inorganic combined materials has become mature; however, the stability of inorganic materials on the surface of organic materials still needs to be improved. SUMMARY

[0004] The present application aims to provide a preparation method of a super-hydrophobic coating, which is prepared by blending the prepared bisvanillin with PEG-400 for the preparation of bio-based polyurethane, improving the environmental performance of the polyurethane, and introducing unsaturation by connecting hydroxyethyl methacrylate; in the subsequent process, the addition of 2-acrylamido-2-methylpropanesulfonic acid modified polyaniline fibers gives the coating corrosion resistance, in addition, it can also be photo-initiated with hydroxyethyl methacrylate, and then the polyaniline fibers are firmly embedded on the resin matrix; the surface of SiO2 is modified by amino propyl triethoxysilane (APTES) and 1H, 1H, 2H, 2H-perfluorodecyl triethoxysilane (PFDTES), APTES and PFDTES are used to provide -NH2 groups and hydrophobic groups respectively, -NH2 groups can act as a curing agent for bisphenol A diglycidyl ether, and after the curing of bisphenol A diglycidyl ether, an interpenetrating network is formed with polyurethane, increasing the water resistance, corrosion resistance and strength of the coating, and the ring-opening of bisphenol A diglycidyl ether induced by -NH2 can better adhere to the metal surface.

[0005] The technical problem to be solved by the present application is that the hydrophobicity of organic-inorganic combined materials has become mature; however, the stability of inorganic materials on the surface of organic materials still needs to be improved.

[0006] The purpose of the application can be achieved by the following technical solutions:

[0007] A preparation method of a super-hydrophobic coating layer, comprising the following steps:

[0008] S1, uniformly mix bisphenol A diglycidyl ether and poly(methyl methacrylate) with a mass fraction of 30-50% at 140℃, add curing agent particles and stir for 5min to obtain a blend;

[0009] S2, dissolve the photoinitiator in the active diluent to form a uniform mixture, then add the modified polyurethane adhesive, the blend and the modified polyaniline fiber to obtain a sprayable colloidal suspension;

[0010] S3, then uniformly spray the sprayable colloidal suspension onto the surface of the substrate to obtain the super-hydrophobic coating layer.

[0011] Further, the curing agent particles are prepared by the following steps:

[0012] 1H, 1H, 2H, 2H-perfluorodecyl triethoxysilane is gradually added to a mixture of deionized water, ammonia, ethanol and functionalized silica nanoparticles, then the mixed solution is stirred at 40℃ for 24 hours, finally the precipitate is recovered by centrifugation, washed with ethanol for 3 times, dried overnight, and ground into a powder with a particle size of 10-30nm to obtain the curing agent particles, wherein the amount ratio of 1H, 1H, 2H, 2H-perfluorodecyl triethoxysilane, deionized water, ammonia, ethanol and functionalized silica nanoparticles is 1mL:10mL:4mL:90mL:2g.

[0013] Further, the functionalized silica nanoparticles are prepared by the following steps:

[0014] Ethanol and ammonia are mixed and stirred for 10 minutes, tetraethyl orthosilicate is gradually added to the solution, after continuous stirring for 10 minutes, aminopropyl triethoxysilane is added, stirred at room temperature for 20 hours, then the temperature is raised to 75℃ and stirred for another 2 hours, the obtained product is centrifuged, washed with ethanol for 3 times, dried overnight, and ground into a powder with a particle size of 20-50nm to obtain the functionalized silica nanoparticles, wherein the volume ratio of ethanol, ammonia, tetraethyl orthosilicate and aminopropyl triethoxysilane is 50:2:5:0.8.

[0015] In the above reaction process, the surface of SiO2 is modified by aminopropyl triethoxysilane (APTES) and 1H, 1H, 2H, 2H-perfluorodecyl triethoxysilane (PFDTES), and APTES and PFDTES are used to provide -NH2 groups and hydrophobic groups respectively.

[0016] It is to be noted that the -NH2 group provided participates in the curing reaction of the later diglycidyl ether of bisphenol A, acts as a curing agent for the diglycidyl ether of bisphenol A, promotes the curing of the diglycidyl ether of bisphenol A, allows better bonding between the filler and the resin, the interpenetrating network structure between the cured diglycidyl ether of bisphenol A and the polyurethane is formed, which makes the connection between the resin matrix more compact, in addition, the nanoparticles can also be better filled in the polymer, which plays a role in strengthening the mechanical properties and hydrophobicity.

[0017] 1H, 1H, 2H, 2H-Perfluorodecyltriethoxysilane has the following structural formula:

[0018]

[0019] Further, the modified polyurethane adhesive is prepared by the following steps:

[0020] The polyol mixture and 2-dimethylpropionic acid are added to a four-necked flask along with acetone, a condenser is attached to one of the necks of the four-necked flask, a thermocouple, a nitrogen inlet, and a stirring rod of an overhead stirrer are inserted into the remaining necks of the flask, the temperature is raised to 60°C and stirred for 30 minutes;

[0021] IPDI is dissolved in acetone and added dropwise to the reaction mixture, during the addition, the temperature is raised to 80°C, after the addition of IPDI is complete, it is refluxed at 80°C under inert atmosphere for 5 hours, then hydroxyethyl methacrylate is added dropwise to the reaction mixture and the reaction is continued at the same temperature for 3 hours, the reaction temperature is reduced to 50°C for the dropwise addition of TEA, the reaction continues for 1 hour to obtain the modified polyurethane adhesive.

[0022] Further, the polyol mixture is prepared by mixing vanillin with PEG-400 in a molar ratio of (0-0.3) : (0.3-0.6).

[0023] It is to be noted that the molecular weight (MW) of PEG is 400, which is considered in view of the fact that PEG is in a polymerized form and has a higher molecular weight compared to the monomeric form of vanillin, therefore PEG shows its major influence on the final properties of polyurethane. Due to aliphatic bonding, PEG with a higher molecular weight imparts greater flexibility. Therefore, the combination of PEG with a molecular weight of 400 with vanillin provides a good balance between aliphatic and aromatic bonds, thus achieving a balance in mechanical properties.

[0024] Further, vanillin is prepared by the following steps:

[0025] Vanillin is dissolved in water, then ferrous sulfate and sodium persulfate are added as catalysts, the mixture is stirred and reacted at 80 DEG C for 30 minutes, after the reaction is completed, the reaction mixture is filtered using filter paper, washed with 80 DEG C hot water, and dried in a vacuum oven to obtain vanillin.

[0026] The structural formula of vanillin is as follows:

[0027]

[0028] Further, the modified polyaniline fiber is prepared by the following steps:

[0029] Aniline monomer is dissolved in chloroform in an ice bath, ammonium persulfate and 2-acrylamido-2-methylpropanesulfonic acid are dissolved in 80 mL of deionized water, then the aqueous solution is added dropwise to the aniline solution in an ice bath, and the reaction is carried out for 24 hours, after centrifugation at 8000 rpm for 15 minutes, the solid is washed with deionized water and acetone, and freeze-dried for 24 hours to obtain the modified polyaniline fiber.

[0030] The structural formula of the modified polyaniline fiber is as follows:

[0031]

[0032] Further, the spraying is performed 3-5 times, and the coating thickness is 85-100 um.

[0033] The beneficial effects of the present application are:

[0034] (1) In the technical scheme of the present application, 800 mesh sandpaper is used to wear the coating at a pressure of 2.2 KPa, and the results show that the coating still maintains superhydrophobicity after 200 wear cycles, with a water contact angle of 155°.

[0035] (2) In the technical scheme of the present application, after 200 wear cycles in the sandpaper wear test, the water contact angle of the coating is 147°, and the coating has a small mass and thickness loss during the wear process, with an average thickness of 80 um.

[0036] (3) In the technical scheme of the present application, SiO2 is surface modified by aminopropyl triethoxysilane (APTES) and 1H, 1H, 2H, 2H-perfluorodecyl triethoxysilane (PFDTES), APTES and PFDTES are used to provide -NH2 groups and hydrophobic groups respectively, the -NH2 groups provided participate in the curing reaction of bisphenol A diglycidyl ether in the later stage, act as a curing agent of bisphenol A diglycidyl ether, promote the curing of bisphenol A diglycidyl ether, and make the filler and the resin better combined, the bisphenol A diglycidyl ether after curing forms an interpenetrating network structure with the polyurethane, making the connection between the resin matrix more compact, in addition, the nanoparticles can also be better filled in the polymer, playing the effect of strengthening mechanical properties and hydrophobicity.

[0037] (4) In the technical scheme of the present application, the prepared bisvanillin is blended with PEG-400 for the preparation of bio-based polyurethane, the environmental performance of the polyurethane is improved, and the unsaturation is introduced by the connected hydroxyethyl methacrylate; in the subsequent process, the addition of the polyaniline fiber modified by 2-acrylamido-2-methylpropanesulfonic acid gives the coating corrosion resistance, in addition, the polyaniline fiber can also be firmly embedded on the resin matrix by light initiation with the hydroxyethyl methacrylate. BRIEF DESCRIPTION OF DRAWINGS

[0038] Figure 1 is the chemical equation for preparing the polyurethane adhesive of the present application;

[0039] Figure 2 Chemical equation for grafting polyurethane adhesive with hydroxyethyl methacrylate. DETAILED DESCRIPTION

[0040] The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor fall within the scope of protection of the present application.

[0041] Preparation Example 1

[0042] The curing agent particles are prepared by the following steps:

[0043] A1, 50 mL of ethanol and 2 mL of ammonia water are mixed and stirred for 10 minutes, 5 mL of tetraethyl orthosilicate is gradually added to the solution, after continuous stirring for 10 minutes, 0.8 mL of aminopropyl triethoxysilane is added, stirring at room temperature for 20 hours, then the temperature is increased to 75°C and stirring is continued for 2 hours, the obtained product is centrifuged, washed with ethanol for 3 times, dried overnight, ground into 35 nm powder, and functionalized silica nanoparticles are obtained;

[0044] A2, 1 mL of 1H, 1H, 2H, 2H-perfluorodecyltriethoxysilane was gradually added to a mixture of 10 mL of deionized water, 4 mL of ammonia water, 90 mL of ethanol, and 2 g of functionalized silica nanoparticles, then the mixed solution was stirred at 40°C for 24 hours, and finally the precipitate was recovered by centrifugation, washed with ethanol 3 times, dried overnight, ground into a 20 nm powder, to obtain the curing agent particles.

[0045] Preparation Example 2

[0046] The modified polyaniline fiber was prepared by the following steps:

[0047] 1 mL of aniline monomer was dissolved in 80 mL of chloroform in an ice bath, 2 mg of ammonium persulfate and 0.2 g of 2-acrylamido-2-methylpropanesulfonic acid were dissolved in 80 mL of deionized water, then the aqueous solution was added dropwise to the aniline solution in an ice bath, and the reaction was carried out for 24 hours. After centrifugation at 8000 rpm for 15 minutes, the solid was washed with deionized water and acetone, and freeze-dried for 24 hours to obtain the modified polyaniline fiber.

[0048] Preparation Example 3

[0049] The vanillin was prepared by the following steps:

[0050] 6 g of vanillin was dissolved in 400 mL of water, then 0.25 g of ferrous sulfate and 5 g of sodium persulfate were added as catalysts, and the mixture was stirred at 80°C for 30 minutes. After the reaction was completed, the reaction mixture was filtered using filter paper, washed with hot water at 80°C, and dried in a vacuum oven to obtain the vanillin.

[0051] Preparation Example 4

[0052] The polyol mixture was prepared by mixing vanillin and PEG-400 in a molar ratio of 0.3:0.3.

[0053] Preparation Example 5

[0054] The polyol mixture was prepared by mixing vanillin and PEG-400 in a molar ratio of 0.18:0.42.

[0055] Preparation Example 6

[0056] The polyol mixture was prepared by mixing vanillin and PEG-400 in a molar ratio of 0.06:0.54.

[0057] Preparation Example 7

[0058] The polyol was PEG-400.

[0059] Preparation Example 8

[0060] The modified polyurethane adhesive is prepared by the following steps:

[0061] A four-necked flask was charged with 0.6 mol of the polyol mixture of Preparation Example 4 and 0.4 mol of 2-dimethylpropanoic acid together with 100 mL of acetone, a condenser was attached to one of the necks of the flask, a thermocouple, nitrogen inlet and stirrer bar of an overhead stirrer were inserted into the remaining necks of the flask, the temperature was raised to 60°C and stirred for 30 minutes;

[0062] 2 mol of IPDI was dissolved in 500 mL of acetone and added dropwise to the reaction mixture, during the addition the temperature was raised to 80°C, after the addition of IPDI was complete, it was refluxed at 80°C under inert atmosphere for 5 hours, then 1 mol of hydroxyethyl methacrylate was added dropwise to the reaction mixture and the reaction was continued at the same temperature for 3 hours, the reaction temperature was reduced to 50°C for the dropwise addition of 0.6 mol of TEA, the reaction was continued for 1 hour to obtain the modified polyurethane adhesive.

[0063] Preparation Example 9

[0064] The difference between this preparation example and Preparation Example 8 is that the polyol mixture of Preparation Example 4 is replaced by the substance prepared in Preparation Example 5, and the remaining steps and raw materials are the same as Preparation Example 8.

[0065] Preparation Example 10

[0066] The difference between this preparation example and Preparation Example 8 is that the polyol mixture of Preparation Example 4 is replaced by the substance prepared in Preparation Example 6, and the remaining steps and raw materials are the same as Preparation Example 8.

[0067] Preparation Example 11

[0068] The difference between this preparation example and Preparation Example 8 is that the polyol mixture of Preparation Example 4 is replaced by the substance prepared in Preparation Example 7, and the remaining steps and raw materials are the same as Preparation Example 8.

[0069] Example 1

[0070] A method for preparing a super-hydrophobic coating, comprising the following steps:

[0071] S1, 70 g of bisphenol A diglycidyl ether and 30 g of polymethyl methacrylate were mixed uniformly, 2.6 g of curing agent particles were added and stirred for 5 min to obtain a blend;

[0072] S2, 2 g of photoinitiator IRGACOR651 was dissolved in 30 g of active diluent tripropyleneglycol diacrylate to form a uniform mixture, then 68 g of the modified polyurethane adhesive prepared in Preparation Example 8, 2.2 g of the blend and 1.3 g of modified polyaniline fiber were added to obtain a sprayable colloidal suspension;

[0073] S3, then the sprayable colloidal suspension is uniformly sprayed onto the surface of the substrate, to obtain the super-hydrophobic coating.

[0074] Example 2

[0075] A method for preparing a super-hydrophobic coating comprises the following steps:

[0076] S1, 70g of bisphenol A diglycidyl ether and 30g of polymethyl methacrylate are uniformly mixed, 2.6g of curing agent particles are added and stirred for 5min, to obtain a blend;

[0077] S2, 2g of photoinitiator IRGACOR651 is dissolved in 30g of active diluent dipropylene glycol diacrylate to form a uniform mixture, then 68g of the modified polyurethane adhesive prepared in Preparation Example 9, 2.2g of the blend and 1.3g of modified polyaniline fiber are added, to obtain a sprayable colloidal suspension;

[0078] S3, then the sprayable colloidal suspension is uniformly sprayed onto the surface of the substrate, to obtain the super-hydrophobic coating.

[0079] Example 3

[0080] A method for preparing a super-hydrophobic coating comprises the following steps:

[0081] S1, 70g of bisphenol A diglycidyl ether and 30g of polymethyl methacrylate are uniformly mixed, 2.6g of curing agent particles are added and stirred for 5min, to obtain a blend;

[0082] S2, 2g of photoinitiator IRGACOR651 is dissolved in 30g of active diluent dipropylene glycol diacrylate to form a uniform mixture, then 68g of the modified polyurethane adhesive prepared in Preparation Example 10, 2.2g of the blend and 1.3g of modified polyaniline fiber are added, to obtain a sprayable colloidal suspension;

[0083] S3, then the sprayable colloidal suspension is uniformly sprayed onto the surface of the substrate, to obtain the super-hydrophobic coating.

[0084] Example 4

[0085] A method for preparing a super-hydrophobic coating comprises the following steps:

[0086] S1, 70g of bisphenol A diglycidyl ether and 30g of polymethyl methacrylate are uniformly mixed, 2.6g of curing agent particles are added and stirred for 5min, to obtain a blend;

[0087] S2, 2g of photoinitiator IRGACOR 651 was dissolved in 30g of active diluent tripropylene glycol diacrylate to form a uniform mixture, then 68g of modified polyurethane adhesive prepared in Preparation Example 11, 2.2g of the blend and 1.3g of modified polyaniline fiber were added to obtain a sprayable colloidal suspension;

[0088] S3, then the sprayable colloidal suspension was uniformly sprayed onto the surface of the substrate to obtain a super-hydrophobic coating.

[0089] Example 5

[0090] A method for preparing a super-hydrophobic coating, comprising the following steps:

[0091] S1, 60g of bisphenol A diglycidyl ether and 40g of polymethyl methacrylate were uniformly mixed, 2.6g of curing agent particles were added and stirred for 5min to obtain a blend;

[0092] S2, 2g of photoinitiator IRGACOR 651 was dissolved in 30g of active diluent tripropylene glycol diacrylate to form a uniform mixture, then 68g of modified polyurethane adhesive prepared in Preparation Example 11, 2.2g of the blend and 1.3g of modified polyaniline fiber were added to obtain a sprayable colloidal suspension;

[0093] S3, then the sprayable colloidal suspension was uniformly sprayed onto the surface of the substrate to obtain a super-hydrophobic coating.

[0094] Example 6

[0095] A method for preparing a super-hydrophobic coating, comprising the following steps:

[0096] S1, 50g of bisphenol A diglycidyl ether and 50g of polymethyl methacrylate were uniformly mixed, 2.6g of curing agent particles were added and stirred for 5min to obtain a blend;

[0097] S2, 2g of photoinitiator IRGACOR 651 was dissolved in 30g of active diluent tripropylene glycol diacrylate to form a uniform mixture, then 68g of modified polyurethane adhesive prepared in Preparation Example 11, 2.2g of the blend and 1.3g of modified polyaniline fiber were added to obtain a sprayable colloidal suspension;

[0098] S3, then the sprayable colloidal suspension was uniformly sprayed onto the surface of the substrate to obtain a super-hydrophobic coating.

[0099] Example 7

[0100] A method for preparing a super-hydrophobic coating, comprising the following steps:

[0101] S1, 50 g of bisphenol A diglycidyl ether and 50 g of polymethyl methacrylate were mixed uniformly, 2.6 g of curing agent particles were added and stirred for 5 min to obtain a blend;

[0102] S2, 2 g of photoinitiator IRGACOR651 was dissolved in 30 g of active diluent tripropyleneglycol diacrylate to form a uniform mixture, then 68 g of modified polyurethane adhesive prepared in Preparation Example 11, 2.2 g of the blend and 1.5 g of modified polyaniline fiber were added to obtain a sprayable colloidal suspension;

[0103] S3, then the sprayable colloidal suspension was uniformly sprayed onto the surface of the substrate to obtain a super-hydrophobic coating.

[0104] Example 8

[0105] A method for preparing a super-hydrophobic coating, comprising the following steps:

[0106] S1, 50 g of bisphenol A diglycidyl ether and 50 g of polymethyl methacrylate were mixed uniformly, 2.6 g of curing agent particles were added and stirred for 5 min to obtain a blend;

[0107] S2, 2 g of photoinitiator IRGACOR651 was dissolved in 30 g of active diluent tripropyleneglycol diacrylate to form a uniform mixture, then 68 g of modified polyurethane adhesive prepared in Preparation Example 11, 2.2 g of the blend and 1.7 g of modified polyaniline fiber were added to obtain a sprayable colloidal suspension;

[0108] S3, then the sprayable colloidal suspension was uniformly sprayed onto the surface of the substrate to obtain a super-hydrophobic coating.

[0109] Comparative Example 1

[0110] The difference between this comparative example and Example 1 is that no curing agent particles are added, and the remaining steps and raw materials are implemented synchronously with Example 1.

[0111] Comparative Example 2

[0112] The difference between this comparative example and Example 1 is that the curing agent particles are only modified by 1H, 1H, 2H, 2H-perfluorodecyl triethoxysilane, and the remaining steps and raw materials are implemented synchronously with Example 1.

[0113] Comparative Example 3

[0114] The difference between this comparative example and Example 1 is that no modified polyaniline fiber is added, and the remaining steps and raw materials are implemented synchronously with Example 1.

[0115] Comparative Example 4

[0116] The difference between the present comparative example and Example 1 is that no bisphenol A diglycidyl ether is added in step S1, and the remaining steps and raw materials are the same as in Example 1.

[0117] Comparative Example 5

[0118] The difference between the present comparative example and Example 1 is that no polymethyl methacrylate is added in step S1, and the remaining steps and raw materials are the same as in Example 1.

[0119] The coatings prepared in Examples 1-8 and Comparative Examples 1-5 were subjected to performance tests:

[0120] The water contact angle (CA) of the test sample using a 10 μL drop of deionized water was measured by a water contact angle measuring instrument (JC2000C, China). All values of CA are the average of five measurements in different directions. The coating thickness was measured using a high-precision thickness meter (8500, Nix, Germany).

[0121] The abrasion resistance of the coating was tested by dragging the sample through 800-mesh sandpaper under a pressure of 2.2 KPa. The movement of a straight line by 10 cm was defined as one cycle, and the water contact angle of the coating was recorded after each cycle.

[0122] The pencil hardness was marked on the surface of the coating using a pencil hardness tester according to ASTM D 3363, and the pencil hardness test was performed using an Elcometer 501 with a pencil range of 6B to 6H.

[0123] The acid and alkali resistance test was used to determine the chemical resistance of the coating using a spotting method for 24 h, and then the coating was inspected for defects. The acid and alkali resistance test was performed according to the ASTM D 1308 standard.

[0124] The test results of the water contact angle and the coating thickness after 200 cycles are shown in Table 1 below:

[0125] Table 1

[0126]

[0127] From the comparison of Examples 1-8 and Comparative Examples 1-2 in Table 1 above, it can be seen that the superhydrophobic coating prepared in the examples has better hydrophobic effect, and after 200 cycles of sandpaper, it still maintains good hydrophobicity and coating thickness. It can be seen that the addition of the curing agent particles can well ensure the hydrophobic effect of the coating, and the modification of the curing agent by 1H, 1H, 2H, 2H-perfluorodecyl triethoxysilane imparts the superhydrophobic effect to the coating.

[0128] The hardness and corrosion resistance of the coating are shown in Table 2 below:

[0129] Table 2

[0130]

[0131] A: no effect on coating, B: white spots, C: dark spots, D: loss of adhesion of coating.

[0132] From the above Table 2, Example 4, it can be seen that the addition of bisvanillin can improve the hardness and corrosion resistance of the coating. From the comparison of Examples 1-3 and Comparative Examples 1-2, it can be seen that the addition of the curing agent particles can improve the corrosion resistance of the coating.

[0133] From the comparison of Examples 1-3 and Comparative Examples 4-5, it can be seen that the interpenetrating network structure can improve the hardness and corrosion resistance of the coating.

[0134] The above is only an example and description of the present application, and those skilled in the art can make various modifications or supplements to the described specific embodiments or use similar ways to replace, as long as they do not deviate from the invention or exceed the scope defined by the present claims, which shall belong to the protection scope of the present application.

Claims

1. A method of preparing a superhydrophobic coating, characterized by: Comprising the following steps: S1, mixing bisphenol A diglycidyl ether and polymethyl methacrylate uniformly, adding curing agent particles and stirring for 5 min to obtain a blend; S2, dissolving the photoinitiator in the reactive diluent to form a uniform mixture, then adding the modified polyurethane adhesive, the blend and the modified polyaniline fiber to obtain a sprayable colloidal suspension; S3, then uniformly spraying the sprayable colloidal suspension onto the surface of the substrate to obtain a super-hydrophobic coating; The curing agent particles are prepared by the following steps: 1H, 1H, 2H, 2H-perfluorodecyl triethoxysilane is gradually added to a mixture of deionized water, ammonia, ethanol and functionalized silica nanoparticles, then the mixed solution is stirred at 40°C for 24 hours, finally the precipitate is recovered by centrifugation, washed with ethanol for 3 times, dried overnight, ground into powder to obtain the curing agent particles.

2. The method of claim 1, wherein: The amount ratio of 1H, 1H, 2H, 2H-perfluorodecyl triethoxysilane, deionized water, ammonia, ethanol and functionalized silica nanoparticles is 1 mL:10 mL:4 mL:90 mL:2 g.

3. The method of claim 1, wherein: The functionalized silica nanoparticles are prepared by the following steps: Ethanol and ammonia are mixed and stirred for 10 minutes, tetraethyl orthosilicate is gradually added to the solution, after continuous stirring for 10 minutes, aminopropyl triethoxysilane is added, stirred at room temperature for 20 hours, then the temperature is raised to 75°C and stirred for another 2 hours, the resulting product is centrifuged, washed with ethanol for 3 times, dried overnight, ground into powder to obtain the functionalized silica nanoparticles.

4. The method of claim 3, wherein: The volume ratio of ethanol, ammonia, tetraethyl orthosilicate and aminopropyl triethoxysilane is 50:2:5:0.

8.

5. The method of claim 1, wherein: The modified polyurethane adhesive is prepared by the following steps: A mixture of polyols and 2-dimethylpropionic acid is added to a four-necked flask together with acetone, a condenser is connected to one neck of the four-necked flask, a thermocouple, a nitrogen inlet and a stirring rod of an overhead stirrer are inserted into the remaining necks of the flask, the temperature is raised to 60°C and stirred for 30 minutes; IPDI is dissolved in acetone and added dropwise to the reaction mixture, during the addition process, the temperature is raised to 80°C, after the addition of IPDI is completed, it is refluxed at 80°C under inert atmosphere for 5 hours, then hydroxyethyl methacrylate is added dropwise to the reaction mixture and the reaction continues at the same temperature for 3 hours, the reaction temperature is reduced to 50°C to add TEA dropwise, the reaction continues for 1 hour to obtain the modified polyurethane adhesive.

6. The method of claim 5, wherein: The mixture of polyols is prepared by mixing vanillin and PEG-400 according to the molar ratio (0-0.3):(0.3-0.6).

7. The method of claim 6, wherein: The vanillin is prepared by the following steps: Vanillin is dissolved in water, then ferrous sulfate and sodium persulfate are added as catalysts, the mixture is stirred and reacted at 80°C for 30 minutes, after the reaction is completed, the reaction mixture is filtered using filter paper, washed with 80°C hot water, and dried in a vacuum oven to obtain the vanillin.

8. The method of claim 1, wherein: The modified polyaniline fiber is prepared by the following steps: ​ The aniline monomer was dissolved in chloroform in an ice bath, ammonium persulfate and 2-acrylamido-2-methylpropanesulfonic acid were dissolved in 80 mL of deionized water, and then the aqueous solution was added dropwise to the aniline solution in an ice bath, and the reaction was carried out for 24 hours, after centrifugation at 8000 rpm for 15 minutes, the solid was washed with deionized water and acetone, and freeze-dried for 24 hours to obtain modified polyaniline fibers.

9. The method of claim 1, wherein: The spraying times are 3-5 times, and the coating thickness is 85-100 um.

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